A snow-covered C-130 Hercules sits on the flightline at Yokota Air Base, Japan, during a snowstorm, Feb. 8, 2014. Increasingly drastic weather patterns and concerns over global warming are being scrutinized by the Pentagon, defense officials said in a plan released Monday. (Osakabe Yasuo/ U.S. Air Force)

Drastic weather, rising seas and changing storm patterns could become “threat multipliers” for the United States, vastly complicating security challenges faced by American forces, the Pentagon said in a new report on the impact of climate change released Monday.

The report, described as a “climate change adaptation roadmap,” included a foreword from Defense Secretary Chuck Hagel in which he urged the nation’s military’s planners to grapple now with the implications of a warming planet, even as scientists are “converging toward consensus on future climate projections.”

“Politics or ideology must not get in the way of sound planning,” Hagel said. “Our armed forces must prepare for a future with a wide spectrum of possible threats, weighing risks and probabilities to ensure that we will continue to keep our country secure.”

The plan was released as Hagel attended a conference in Peru with his counterparts from across North and South America.

In remarks released alongside the 20-page report, Hagel said the Pentagon is nearly done with a survey that will assess the vulnerability of its military installations to climate change. He cited the Hampton Roads region of Virginia as an example of an area that has both military bases and recurrent flooding, adding that defense officials are developing plans to address a projected sea-level rise of about 1.5 feet in the next 20 to 50 years.

The Defense Department developed a climate change working group in 2012. The Pentagon must assess the potential effects of the phenomenon on the frequency of disaster relief missions, additional military operations in the Arctic and instability within and among other countries, the new climate change plan says.

“The Department will need to monitor these developments and decide which situations will require intervention based on U.S. security interests — either preemptively through security cooperation and capacity building, or with stability measures once conditions escalate,” the plan says.

It isn’t the first time the military has examined the potential effects on climate change. The Navy, for example, released a climate change “roadmap” in April 2010, saying that while climate change probably wouldn’t lead to conflict on its own, “it may be a contributing factor.”

The new report suggests broader cooperation and emphasis on the issue. Hagel said the Defense Department will work with the State Department, the U.S. Agency for International Development and the Federal Emergency Management Agency, among other organizations. He also said the United States must work with other nations.

“Climate change is a global problem,” the secretary said. “Its impacts do not respect national borders. No nation can deal with it alone. We must work together, building joint capabilities to deal with these emerging threats.”